1. Field of the Invention
The present invention relates to a machine component monitoring system for monitoring statuses, such as the presence or absence of an abnormality, and/or lifetime of machine components employed in a machine system such as an iron working plant or a paper making plant, that are equipped with the machine components, each machine component having rolling elements such as rolling bearings, constant speed joints, or ball screw mechanisms, to a machine component monitoring and diagnosing system, enabling a manufacturer to monitor and diagnose the statuses at a remote location, and to a machine component monitoring, diagnosing, and selling system adding merchandise information to results of diagnosis after the machine components have been monitored and diagnosed.
2. Description of the Related Art
As is well known to those skilled in the art, an iron working plant or a paper making plant employs a number of rolls, and roll support bearings are used to support those rolls. The roll support bearings, particularly, rolling roll support bearings used in a continuous casting machine, are used under a relatively large load and at an elevated temperature, that is under severe operating conditions. Since sudden interruption of the operation of the plants as a result of an abnormality occurring in some of the support bearings would likely result in a considerable loss, the support bearings are regularly replaced at intervals of a few months.
During the routine replacement, it often occurs that some support bearings that are still usable are replaced in anticipation of safety. Thus, some of the support bearings are used uneconomically, resulting in an increase of the cost of maintenance of the facilities. If there was a way to grasp the status of the lifetime of each support bearing, the time span between the succeeding replacements of the support bearings can be prolonged. Accordingly, attempts have been made to use vibrations sensors to monitor the status of the lifetime of each support bearing, but since the number of the support bearings used is considerable, a relatively high cost is incurred in monitoring those support bearings.
As is discussed above, the roll support bearings used in the iron working plant or the paper making plant are monitored by the use of the above-described vibration sensors, to determine the status of the lifetime of each support bearing. But since each support bearing is of a relatively large size, the iron working plant and the paper making plant often perform their own monitoring schemes to determine and diagnose the status of the lifetime of each support bearing using the vibration sensors as a routine for maintenance of the facilities. Specifically, based on the status of the lifetime obtained as a result of monitoring, the iron working plant or the paper making plant set up a plan to replace the machine components, ask the manufacturer of the support bearings for estimates for the replacement, and order the support bearings to be replaced after the stock, the price, and the expected date of delivery have been confirmed.
Similar monitoring and diagnosis are also performed in other facilities, such as a production line, or automobile or railway train servicing facilities in traffic industries. Where the particular plant cannot perform the diagnosis on its own, the plant makes it practice to call for a technician from the bearing manufacturer to make a diagnosis in situ at the plant.
But with a diagnosing instrument used in the iron working plant or the paper making plant, and also with the technician in the other plants, a problem has been encountered that an accurate diagnosis is difficult to achieve. In the event of an abnormality resulting from an erroneous diagnosis, a loss such as sudden scramming of the plant would occur. For this reason, some spare bearings have to be stocked in hand in anticipation of the erroneous diagnosis. By way of example, a paper making system used in the paper making plant makes use of 200 to 300 rolls with their opposite ends rotatably supported by respective bearings, thus utilizing a relatively large number of the bearings. Accordingly, for all of those bearings to keep in good operating conditions, monitoring and diagnosing have to be performed frequently and on a regular basis, thus requiring a relatively large number of spare bearings to be stored in anticipation of future replacement.
Employment of diagnosing instruments and/or technicians in the iron working plant or the paper making plant is indeed uneconomical since the diagnosing instruments and/or the technicians sometimes lead to unnecessary expenditure.
Also, if after the machine components, i.e., the bearings have been diagnosed at the iron working plant or the paper making plant, the attendant worker consults with a sales representative sent from the bearing manufacturer, then a relatively large amount of time and labor required, and because of it, it often occurs that delivery of the ordered bearing will be delayed. Under these circumstances, the plant would be required to store the spare bearings for use in the future. On the other hand, even the bearing manufacturer would be required to store a large amount of bearings in anticipation of varying orders. Additionally, the bearing manufacturer has to employ personnel for sales activities, and thus has a relatively large amount of expenditure for personnel shift.